Agathidium
Agathidium mandibular
Agathidium is a beetle species of the family Leiodidae. Within the subfamily Leiodinae Agathidium belongs to the tribe Agathidiini.
- 2.1 slime molds as a food source
- 2.2 Stand mushrooms as a substrate
- 3.1 Naming by People
- 3.2 Selected species
- 4.1 Notes and references
- 4.2 Literature
Features
The beetles of the genus Agathidium are very small, they reach a length of 1-6 millimeters. The ranges in color from reddish brown through dark brown to black, eye-catching colors are rarely represented. Many species of the genus are flightless. Elytra and pronotum are shiny and usually punctured. The points are arranged irregularly or occasionally in rows. Are the beetles of fungal spores covered, you can only exceptionally difficult to identify them in the laboratory.
The species of the genus Agathidium have as the other members of the tribe Agathidiini walking legs, in contrast to the results summarized in the tribe Leiodini sponge spider beetles, have the grave legs.
Spherical shape
Your back plate and pronotum are usually strongly arched, but there are also elongated oval types. Some species, such as fawcettae Agathidium can be rolled up to an almost complete sphere. In this position, the legs are drawn, and hidden the sensor in separate grooves on the underside of the head. The wide side edges of the neck flange to overlap the edges of the top wing, so that the entire body is protected.
Asymmetrical horn formation of the males
The males of some species, such as difforme Agathidium and Agathidium pulchrum have on the left mandible horn- like appendage which is used to distribute male rivals. Other gender differences are the wide first Tarsenglieder the front and middle pairs of legs of males or a tooth-like formation on the thighs of the hind legs in some species.
Habitat and behavior
Similar to the related genus Anisotoma the species of the genus Agathidium on slime molds ( Eumycetozoa ) are specialized. You to and from the slime molds live. The habitat of the beetle is therefore where the slime molds can develop: under bark, in rotting wood or in the leaf litter of forests. As the slime molds are common beetles of the genus Agathidium world, but they are mainly found in the northern hemisphere, where they occur from the forests of the temperate zone to the tropical rain forests of the montane zone.
Slime molds as a food source
The affinity of the genus Agathidium to the slime molds is clear when they are in the vicinity of the designated as Sporokarp spore-forming fruiting bodies. Due to the severity of the mandibles of some Agathidium species is believed to break up the spores of the slime molds and use as a food source. However, the major food of the beetle could be the plasmodial stages of slime molds when the amoeba -like unicellular organisms temporarily form an organizational form that moves on the ground as a stringy, slimy mass. Individual beetles were observed on such plasmodia both in the laboratory and in nature. Often, the slime molds are but because of the small size of protozoa and their secretive lifestyle difficult to detect.
The slime molds on which Agathidium species are found include almost all types of Real slime molds ( Myxogastria ), including the Nearctic genus Physarum, the type Brefeldia maxima and the species of the genus Fuligo with the Yellow Lohblüte ( Fuligo septica ).
Stand mushrooms as a substrate
In nature, there will therefore be the beetles of the genus Agathidium apparently. , Even without clear association with slime molds, eg on different stand mushrooms, which also include a number of tree fungi and the known agarics However, it is still controversial whether the beetles can feed directly from this stand fungi or slime molds graze here, living on the decaying fruit bodies of mushrooms or toadstools. For Agathidium aristerium is sufficiently clear that it feeds on the slime mold Physarum polycephalum, which on the fruiting bodies of the oyster - sideways ( Pleurotus ostreatus ) is often encountered. Conversely, you can be found in the digestive tract of Agathidium seminulum, a beetle that on the Scaly Polypore ( Polyporus squamosus ) found spores of this fungus. This suggests that a diet directly from the fruiting bodies of the fungus. What role the genus Agathidium plays in spreading the spores of the slime molds or the stand mushrooms, is still unclear.
Taxonomy and Nomenclature
The genus Agathidium was first mentioned in 1797 by Georg Wolfgang Franz Panzer in his work fauna insectorum Germanicae initialized, or Germany insects.
Designation by People
It is striking that many beetle species described recently from the genus Agathidium have an eponym in scientific names, ie they are named after a famous personality. Agathidium bushi, Agathidium cheneyi, Agathidium rumsfeldi and Agathidium are vaderi species which of the two former Cornell entomologists Quentin Wheeler ( after a stay at the Natural History Museum in London since 2006 at Arizona State University) and Kelly Miller (now at Brigham Young University ) were named after George W. Bush, Dick Cheney, Donald Rumsfeld, or Darth Vader.
Selected species
In Europe, approximately 100 species of the genus Agathidium of 4 subgenera are common. In the Oriental, a Faunenreich in the biogeographic region United Paläotropis, there are more than 350 species. It is expected that many more species that previously went unnoticed because of the small size of beetles, are discovered and described.
- Agathidium arcticum Thomson, 1862
- Agathidium atrum ( Paykull, 1798)
- Agathidium badium Erichson, 1845
- Agathidium bushi Miller et Wheeler, 2005
- Agathidium cheneyi Miller et Wheeler, 2005
- Agathidium confusum Brisout de Barneville, 1863
- Agathidium convexum Sharp, 1866
- Agathidium discoideum Erichson, 1845
- Agathidium gutianense Angelini et Cooter, 1999
- Agathidium haemorrhoum Erichson, 1845
- Agathidium laevigatum Erichson, 1845
- Agathidium mandibular storm, 1807
- Agathidium marginatum storm, 1807
- Agathidium nigrinum storm, 1807
- Agathidium nigripenne (Fabricius, 1792)
- Agathidium pallidum ( Gyllenhal, 1827)
- Agathidium pisanum Brisout de Barneville, 1872
- Agathidium plagiatum ( Gyllenhal, 1810)
- Agathidium pulchellum Wankowicz, 1869
- Agathidium rotundatum ( Gyllenhal, 1827)
- Agathidium rumsfeldi Miller et Wheeler, 2005
- Agathidium seminulum (Linnaeus, 1758)
- Agathidium vaderi Miller et Wheeler, 2005
- Agathidium varians Beck, 1817